Finding the Fourth Proportional to 1,005.50, 1,387.67 and 591.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.50 : 1,387.67 = 591.58 : x
2. Step 2: Convert to fraction form
   1,005.50/1,387.67 = 591.58/x
3. Step 3: Cross multiply
   1,005.50x = 1,387.67 × 591.58
4. Step 4: Simplify right side
   1,005.50x = 820,917.82
5. Step 5: Solve for x
   x = 820,917.82/1,005.50
6. Step 6: Final answer
   x = 816.43